Oh, ferrofluids, is there anything you can't do? Researchers led by MIT's Markus Zahn have devised a technique for separating oil from water. Using magnets. Tiny, tiny magnets that temporarily transform polluting oil into a magnetically manipulable ferrofluid.

Zahn and his team say that after separating the oil from the water, the magnetic nanoparticles themselves could then be removed from the oil and stored for later use. "The process may seem simple," says Zahn, "but it is, inherently, supposed to be simple."